In recent years, a driving support system has been developed, for example, to control various pieces of vehicle equipment mounted in a vehicle, such as an automobile, in accordance with a vehicle state or a traveling environment of the vehicle. This driving support system identifies the vehicle state or traveling environment in response to signals and the like acquired by various sensors mounted in the vehicle. Based on this distinction result, the driving support system performs control and the like of the vehicle equipment.
For example, in the driving support system disclosed by Patent Document 1, information showing a vehicle state is acquired from a key switch, a shift lever, a vehicle speed sensor, an air bag, an antitheft device, and the like that are mounted in a vehicle. The driving support system has a vehicle situation definition table in which information contents concerning the key switch, the shift lever, the vehicle speed sensor, the air bag, the antitheft device, and the like and pre-defined vehicle situations (vehicle states) are correlated with each other. In this vehicle situation definition table, situations, such as “during parking”, “during stopping”, “traveling (moving forward)”, “moving backward”, “when collided”, and “when stolen”, are defined as the vehicle situations. An operation system including the thus formed vehicle situation definition table concludes that the vehicle situation is “during parking” with reference to the vehicle situation definition table, for example, when the key switch indicates “Off”, when the shift lever indicates “P”, and when the vehicle speed indicates “0 km per hour”. Based on the concluded vehicle situation, the driving support system determines the priority of actions of various pieces of vehicle equipment mounted in the vehicle. For example, when the concluded vehicle situation is “during parking”, the driving support system determines that the priority of vehicle equipment other than a keyless entry having high action priority is low when parked, and the driving support system performs control to reduce the amount of electric power supply to vehicle equipment other than the keyless entry. As a result, the amount of electric power supply to vehicle equipment is controlled in accordance with vehicle situations in each case, and the amount of electric power consumption in the vehicle is reduced.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-237913